Setting The Vacuum - Roberts Gorden Corayvac CRV-B Series Installation, Operation & Service Manual

CRV-S I , O
ERIES NSTALLATION PERATION AND
4. If any abnormal operation occurs, see the trou-
bleshooting section of the service instructions.

13.4 Setting the Vacuum

1. Set temperature setpoints above room tempera-
ture. See that all burners are operating properly.
2. Allow at least ½ hour operation for temperature
to normalize, then check system vacuum bal-
ance. Vacuum can be measured by inserting a
manometer hose into the end vent as shown on
Page 65, Figure 48. Normal end vent vacuum
should be set at approximately 2.5'' wc to 3.0'' wc
(hot).
Vacuum adjustments are made by means of the
damper in the pump inlet and the adjustable
damper coupling(s) in the system. Check the
vacuum at all end vents and then adjust the
damper coupling to obtain equal vacuum
readings of 2.5'' wc to 3.0'' wc. If end vent
vacuum exceeds 3.0" wc, adjust the pump inlet
damper until vacuum readings are 2.5'' wc to
3.0'' wc.
With systems designed to operate at maximum
vacuum, it may not be possible to obtain
vacuum differential readings at or slightly above
2.5'' wc. If so, adjust the damper couplings to
maximum but equal vacuum reading. Be sure to
lock all dampers securely after adjustment.
3. Reset temperature setpoints to desired room
temperature.
4. If heat is not required, turn off main switch and
close the main gas valve.
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S M
ERVICE ANUAL